Ship A is located 4 km north and 3 km east of ship B. Ship A has a velocity of 20 kmh-1 towards the south and ship B is moving at 40 kmh-1 in a direction 37o north of east. Take x- and y-axes along east and north directions, respectively.

v→AW=−20j^v→BW=32i^+24j^v→AB=v→AW−v→BW=−32i^−44j^dr→ABdt=v→AB=−32i^−44j^∫3i+4j^r→AB dr→AB=−∫at 32dti^−∫0t 44dtj^r→AB=(3−32t)i^+(4−44t)j^At t=1/11h,j^  component of rAB→ is zero. At this time, its i^  component is 3−32t=3−3211=111kmIt means at t = 1/11 h, A will be east of B. So at no time, A will be west of B.